Mass spectrometry (“MS”) and tandem mass spectrometry (“MS-MS”) are well established methods of identifying unknown compounds. Exact mass measurement of molecular ions and/or fragment ions can give information as to the possible elemental composition and functional groups present in an unknown compound. Matching of mass spectra with library spectra can help to identify compounds or identify structurally related compounds. This information coupled with other techniques such as optical spectroscopy or NMR etc. can give a high degree of specificity in compound identification. However, these methods alone can often result in ambiguity with several candidate compounds being assigned to the unknown.
It is desired to provide an improved method of mass spectrometry.